GLOBAL TB PROGRAMME
Systematic screening for active TB – operational manual and tool to help
prioritization
Wolfheze 2015
Knut Lönnroth, Global TB ProgrammeWHO
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GLOBAL TB PROGRAMME
Strong recommendations = Should be screened in all settings
1. Household contacts and other close contacts should be systematically screened for active TB.
2. People living with HIV should be systematically screened for active TB at each visit to a health facility.
3. Systematic screening for active TB should be done in current and former workers in workplaces with silica exposure
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GLOBAL TB PROGRAMME
Conditional recommendations = prioritization needed
4. Systematic screening for active TB should be considered in prisons and other penitentiary institutions. (including staff)
5. Systematic screening for active TB should be considered in people with untreated fibrotic CXR lesion.
6. In settings where the TB prevalence is ≥100/100,000 in the general population, systematic screening for active TB should be considered among people who are seeking care or who are in care and belong to selected risk groups (see remarks, including staff)
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GLOBAL TB PROGRAMME
Conditional recommendations, cont.
7. A. Systematic screening may be considered for geographically defined sub-populations with extremely high levels of undetected TB (>1% prevalence)
B. Systematic screening may be considered also for other sub-populations with very poor health care access, such as urban slum dwellers, homeless people, people living remote areas with poor access, indigenous populations, migrants, and other vulnerable groups.
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Operational guide
GLOBAL TB PROGRAMME
Planning & implementation cycle
1. Situation assessment / 6. Monitoring
and evaluation
2. (Re-)Define goals and specific
objectives
3. (Re-) prioritization of
risk-groups
4. Choose screening and
diagnostic algorithms
5. Planning, budgeting,
implementation
GLOBAL TB PROGRAMME
Tool for prioritization of risk groups(slides from Cecily Miller, UCSF)
Estimates the following for each risk group and each algorithm:
Case-finding yield (true and false positive) Number needed to screen to detect one true case Total cost Cost per true case detected
Allows for comparison of estimates Across risk groups Across screening algorithms
GLOBAL TB PROGRAMME
Step 1– Select the country User begins by selecting the country for exploration:
Country selection auto-populates data on: Total population size TB prevalence per 100,000 HIV prevalence Household size (when available)
Cambodia
GLOBAL TB PROGRAMME
Step 2 – Select risk groups
PLHIV
Contacts
Miners
Diabetics
GLOBAL TB PROGRAMME
Step 3 – Estimating risk group size
2 ways to specify population size of each risk group:1. Estimate size of risk group as % of country population (default)2. Estimate absolute size of risk group
PLHIV
Contacts
Miners
Diabetics
GLOBAL TB PROGRAMME
Step 4 – Estimating TB prevalence in each risk group
2 ways to specify TB prevalence within risk groups:1. Enter or estimate relative risk of TB in risk group compared to
general population (default)2. Enter or estimate absolute TB prevalence per 100k
PLHIV
Contacts
Miners
Diabetics
GLOBAL TB PROGRAMME
Step 5 – Reachability & acceptability
Contacts
PLHIVMiners
Diabetics
Enter the % of the risk group expected to be reachable
Enter the % of the risk group expected to accept screening Findings from acceptability systematic review pre-filled as suggested
values
GLOBAL TB PROGRAMME
Algorithms (default, with changeable values for sensitivity and specificity)
1a. Cough screen Sputum smear microscopy 1b. Cough screen Xpert1c. Cough screen CXR Sputum smear microscopy1d. Cough screen CXR Xpert
2a. Any symptom screen Sputum smear microscopy2b. Any symptom screen Xpert2c. Any symptom screen CXR Sputum smear microscopy2d. Any symptom screen CXR Xpert
3a. CXR Sputum smear microscopy3b. CXR Xpert
Note: - Clinical diagnosis / empirical treatment not considered for persons negative on diagnostic test in current version- Culture can be included, by replacing Xpert assumptions
GLOBAL TB PROGRAMME
Step 6 – costs
User estimates cost of per person screened:1. Test cost2. Operational cost
GLOBAL TB PROGRAMME
https://wpro.shinyapps.io/screen_tb/
GLOBAL TB PROGRAMME
Total potential yield
GLOBAL TB PROGRAMME
GLOBAL TB PROGRAMME
No. of true and false positive cases
Cough sm
ear m
icroscopy
Cough C
XR
Xpert
CX
R X
pert
Alg
orith
mC
XR
Xpert
Cough C
XR
Xpert
Cough sm
ear m
icroscopy
GLOBAL TB PROGRAMME
Costs per true case, across algorithms:
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Incremental cost-effectiveness
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Tool considerations & limitations Focus on pulmonary TB (bacteriologically confirmable)
The tool is exploratory, not for detailed planning purposes Tool estimates are based on several assumptions The uncertainty of each estimate compounds the uncertainty of the
overall estimates
Does not model the impact on transmission and TB incidence
Does not estimate patient cost (only provider)
Algorithm options developed mostly for low- and middle-income countries
GLOBAL TB PROGRAMME
Thank you
Acknowledgements
Cecily Miller Nobu NishikioriAnja van't Hoog
Screening operational guide review committee
https://wpro.shinyapps.io/screen_tb/ Send feedback to [email protected] & [email protected].
